<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>hello vue</title>
</head>
<style type="text/css">
    .container .cart {
        width: 300px;
        margin: auto;
    }

    .container .title {
        background-color: lightblue;
        height: 40px;
        line-height: 40px;
        text-align: center;
        /*color: #fff;*/
    }

    .container .total {
        background-color: #FFCE46;
        height: 50px;
        line-height: 50px;
        text-align: right;
    }

    .container .total button {
        margin: 0 10px;
        background-color: #DC4C40;
        height: 35px;
        width: 80px;
        border: 0;
    }

    .container .total span {
        color: red;
        font-weight: bold;
    }

    .container .item {
        height: 55px;
        line-height: 55px;
        position: relative;
        border-top: 1px solid #ADD8E6;
    }

    .container .item img {
        width: 45px;
        height: 45px;
        margin: 5px;
    }

    .container .item .name {
        position: absolute;
        width: 90px;
        top: 0;
        left: 55px;
        font-size: 16px;
    }

    .container .item .change {
        width: 100px;
        position: absolute;
        top: 0;
        right: 50px;
    }

    .container .item .change a {
        font-size: 20px;
        width: 30px;
        text-decoration: none;
        background-color: lightgray;
        vertical-align: middle;
    }

    .container .item .change .num {
        width: 40px;
        height: 25px;
    }

    .container .item .del {
        position: absolute;
        top: 0;
        right: 0px;
        width: 40px;
        text-align: center;
        font-size: 40px;
        cursor: pointer;
        color: red;
    }

    .container .item .del:hover {
        background-color: orange;
    }
</style>

<body>
    <div id="app">
        <div class="container">
            <my-cart></my-cart>
        </div>
    </div>

    <script type="text/javascript" src="js/vue.js"></script>
    <script type="text/javascript">
        // 标题组件
        var CartTitle = {
            props: ['uname'],
            template: `
                <div class="title" >{{uname}}的商品</div>
            `
        }

        // 列表组件
        var CartList = {
            props: ['dataList'],
            template: `
                <div>
                    <div :key='item.id' v-for='item in dataList' class='item'>
                        <img :src="item.img"/>
                        <div class="name">{{item.name}}</div>
                        <div class="change">
                        <a href="" @click.prevent='sub(item.id)'>－</a>
                        <input type="text" class="num" :value='item.num' @blur='changeNum(item.id, $event)'/>
                        <a href="" @click.prevent='add(item.id)'>＋</a>
                        </div>
                        <div class="del" @click='del(item.id)'>×</div>
                    </div>
                </div>
            `,
            methods: {
                // 子组件调用父组件方法，并传递参数
                changeNum: function (id, event) {
                    this.$emit('change-num', {
                        id: id,
                        type: 'change',
                        num: event.target.value
                    });
                },
                sub: function (id) {
                    this.$emit('change-num', {
                        id: id,
                        type: 'sub'
                    });
                },
                add: function (id) {
                    this.$emit('change-num', {
                        id: id,
                        type: 'add'
                    });
                },
                del: function (id) {
                    // 把id传递给父组件
                    this.$emit('cart-del', id);
                }
            }
        }

        // 结算组件
        var CartTotal = {
            props: ['dataList'],
            template: `
            <div class="total">
                <span>总价：{{total}}</span>
                <button>结算</button>
            </div>
            `,
            computed: {
                total: function () {
                    var t = 0;
                    this.dataList.forEach(item => {
                        t += item.price * item.num;
                    });
                    return t;
                }
            }
        }

        Vue.component('my-cart', {
            data: function () {
                return {
                    username: 'George',
                    list: [{
                        id: 1,
                        name: 'TCL彩电',
                        price: 1000,
                        num: 1,
                        img: 'image/a.jpg'
                    }, {
                        id: 2,
                        name: '机顶盒',
                        price: 1000,
                        num: 1,
                        img: 'image/b.jpg'
                    }, {
                        id: 3,
                        name: '海尔冰箱',
                        price: 1000,
                        num: 1,
                        img: 'image/c.jpg'
                    }, {
                        id: 4,
                        name: '小米手机',
                        price: 1000,
                        num: 1,
                        img: 'image/d.jpg'
                    }, {
                        id: 5,
                        name: 'PPTV电视',
                        price: 1000,
                        num: 2,
                        img: 'image/e.jpg'
                    }]
                }
            },
            template: `
                <div class='cart'>
                    <cart-title :uname="username"></cart-title>
                    <cart-list :dataList="list" @change-num='changeNum($event)' @cart-del='delCart($event)'></cart-list>
                    <cart-total :dataList="list"></cart-total>
                </div>
            `,
            components: {
                'cart-title': CartTitle,
                'cart-list': CartList,
                'cart-total': CartTotal
            },
            methods: {
                changeNum: function (obj) {
                    // 分为三种情况：输入域变更、加号变更、减号变更
                    if (obj.type == 'change') {
                        // 根据子组件传递过来的数据，跟新list中对应的数据
                        this.list.some(item => {
                            item.num = obj.num;
                            // 终止遍历
                            return true;
                        });
                    } else if (obj.type == 'sub') {
                        // 减一操作
                        this.list.some(item => {
                            if (item.id == obj.id) {
                                item.num -= 1;
                                // 终止遍历
                                return true;
                            }
                        });
                    } else if (obj.type == 'add') {
                        // 加一操作
                        this.list.some(item => {
                            if (item.id == obj.id) {
                                item.num += 1;
                                // 终止遍历
                                return true;
                            }
                        });
                    }
                },
                delCart: function (id) {
                    // 根据id删除list中对应的数据
                    // 1、找到id所对应数据的索引
                    var index = this.list.findIndex(item => {
                        return item.id == id;
                    });
                    // 2、根据索引删除对应数据
                    this.list.splice(index, 1);
                }
            }
        });

        var vm = new Vue({
            el: '#app',
            data: {
                msg: 'Hello Vue !'
            }
        });
    </script>
</body>

</html>